Milling apparatus



March 27, 1962 N. szAs z MILLING APPARATUS 2 Sheets-Sheet 1 Filed May22, 1958 BY KSZASZ ADM w smfifi 72%; C. W

ATTORNEY mm Om m oE March 27, 1962 N. SZASZ MILLING APPARATUS 2Sheets-Sheet 2 INVENTOR.

NANDQR $ZASZ y Mm ADMINIZIICRAT X 1 ATTORNEY Filed May 22. 1958 iilnitedrates Fatent @fifice 3,027,101 Patented Mar. 27, 1962 This inventionrelates to milling apparatus and more particularly to an improvedcompact flour milling installation and the construction of specialstacked units for such an installation.

Some attempts have been made in the prior art to arrange flour millingapparatus in a stack or frame in which the stock is fed to successivebreaking or reduction rolls and intermediate sifting devices. One suchunit is shown, for example, in Buchholz United States Patent 97,038, inwhich reciprocating sifters are mounted in a stack between successivesets of milling rolls. Stacked milling units of this type have not beenused extensively. Mechanical difliculties were apparently encountered.Also, modern milling emphasis on the use of air purifiers and gyratorysifters and on complex flows for greater extraction have required anabundance of equipment, and the use of large mill buildings, which areoften many stories high in order to minimize mechanical conveying bymore extensive vertical conveying of the stocks. Thus such stacked millsnever achieved substantial popularity or utility.

With the problems of the prior art in mind, it is one object of thepresent invention to provide an improved stacked milling unit.

Another object is the provision of an improved arrangement ofreciprocating sifters.

It is a further object to provide a stacked milling unit in whichreciprocating sifters are arranged in a particular manner withassociated milling machines.

Another object is a stacked mill arrangement in which undesiredvibrations and bending forces on the frame are reduced to a minimum.

A further object is an improved roller mill unit of minimum verticalheight.

Still another object is an improved roller mill unit which can be hungfrom a supporting frame to eliminate the bulk of a conventional bottomsupport.

Other objects and advantages will be apparent from the followingspecification, in which certain preferred embodiments of the inventionare described. In the drawings which form a part of this application-FIGURE 1 is a side elevation of a single milling unit stack according tothe present invention;

FIG. 2 is a partial perspective view of one of the re ciprocatingsifters of the stack of FIG. 1;

FIG. 3 is a partial View showing details of the driving mechanism forthe sifters;

FIG. 4 is a front View of an improved roller mill unit of minimumvertical height;

FIG. 5 is a sectional view along the line 55 of one end of the device ofFIG. 4; and

FIG. 6 is an end View of the opposite end of the unit of FIG. 4, withcertain portions broken away for clarity.

As shown in FIG. 1, the invention contemplates the use of a supportingframe indicated generally at 10, which includes a central supportingsection 12, and oppositely extending end sections 14 and 16 which are inlongitudinal alignment with each other and with the greater centersection 12. The center support section may include at least two pairs ofvertically extending columns 18 and 20, with one column of each pair ateach side of the machine. The respective end support sections include atleast one pair of vertical columns 22 for end section 14 2 and a pair ofvertical columns 24 for section 16. Upper connecting beams 26 rigidlyconnect the various vertical columns. Additional longitudinal braces 28interconnect the columns 18 and 22, while further beams 30 connectcolumns 20 and 24.

According to the present invention, one or more pairs of reciprocatingclassifying units are mounted in the respective frame portions. Theseclassifying units are arranged in pairs. As shown in FIG. 1, forexample, the uppermost sifters 32 and 34 form a first pair, the next Ilower classifying units 36 and 38 form a second pair, the

next lower classifying units 40 and 42 form a third pair, and the lowestclassifying units 44 and 46 constitute a fourth pair. The individualclassifying units of each pair are arranged in longitudinal alignmentwith each other and extend from the central support portion of the frameinto the opposite end sections of the frame.

As a practical matter it is particularly desirable to arrange the unitsso that they feed their stocks in opposite directions. Thus either theirrespective receiving ends or their discharge ends will be adjacent eachother at the center portion of the frame. In such a case, as notedbelow, when the respective classifiers or sifters of each pair arereciprocated in counterbalancing opposition, a conveying stroke will bebalanced against a conveying stroke and a return stroke against a returnstroke.

It is also possible, especially where the weights of the respectivestocks are relatively small compared to the weights of the classifiersthemselves, to have the classifiers of each pair feed in the samedirection, while they are reciprocated in counterbalancing opposition.

The respective pairs of classifiers are adapted to be driven orreciprocated in counterbalancing opposition to each other by severaldrive shafts 48, 50-, 52, and 54. Shaft 48, for example, is driven by amotor 56 through an intermediate belt 58. A further belt connection 60drives the shaft 50 from shaft 48 through the same motor '56..Similarly, shaft 52 is driven by a motor 62 through belt 64. A furtherbelt 66 drives shaft 54 from shaft '52. These drive shafts are arrangedso that one shaft serves as a common drive for both sifters of a givenpair. The shafts are thus located conveniently at the center of theframe, between the respective Sifters of each pair.

The individual classifying units are supported, in known manner, bysuitable hangers 63 and 72, to provide the desired reciprocatingvibratory movement. As shown in detail in FIGS. 1 and 2, sifter 32 ispivotally connected at 69 to the lower ends of one pair of hangers 68(only one of which is shown). The upper end of this hanger is pivotallycarried by a supporting bracket 70 on the center supporting frame 12.Similarly, the hanger 72 at the opposite end of sifter 32 is carried bya bracket 74 on the end frame. The respective classifiers includesuitable sifting surfaces, such as the screen 76 shown in FIGS. 1 and 2,for classifier 32. This screen surface is supported within the body 78of the sifter and is adapted to receive stock fed into the receiving end92 of the sifter through an inlet 80. Suitable reciprocation of unit 32is adapted to convey the stock from this receiving end to the oppositeor discharge end 94 of the unit and to sift the desired particles downthrough the screen surface 76.

The desired reciprocatory movement is given to classifier 32 in knownmanner by a connecting rod 82, which is pivotally connected at 84 to thesifter. The other end of connecting rod 82 includes an eccentric 86(FIG. 3) driven by shaft 48. A similar eccentric 88 on a connecting rod90 drives the opposite classifier 34 of this first pair. The eccentricsare arranged exactly opposite each other so that the respective siftersare at all times moved in counterbalancing opposition, i.e., eithertoward each other or away from each other. Thus the movemerits of therespective sifting units tend to cancel each other and to minimize theeffective vibrations transmitted to the frame. As set forth above, thisbalancing of vibrations is further enhanced if the directions of feed onthe respective classifiers of a given pair are opposite to each other.In that case, a conveying stroke is opposed to a conveying stroke and areturn stroke to a return stroke. The feeding of substantiallyequivalent weights and types of stock to each sitter of an opposing pairfurther insures the balancing of horizontal forces and the reduction orelimination of forces tending to deflect the vertical coltunns of theframe. Greater flexibility of processing iiow, however, may be obtainedby operating on different desired stocks. Where the stocks provide onlya fraction of the total weight of each sifter, one may process differenttypes and weights of stock on the respective sifters of a given pair inorder to achieve such flexibility. One may also add weight to one sifteror the other to balance the total weights of the opposed units for flowsof different stock weight or to compensate for different sifter weightsdue to construction details. These arrangements and the use of opposedeccentrics on common drive shafts thus counterbalance the major forcesinvolved.

The frequency and amplitude of the reciprocatory vibrations, and theirdirection as determined by the angular orientation of hangers 68 and 72,are adapted to convey the stock in known manner from the receiving endto the discharge end of each classifying unit. Thus in unit 32 thematerial is received at the inner receiving end 92 at the central framearea and conveyed to the outer end portion of the frame across thesifting surface 76. The material which stays above the screen is thendischarged at 94, while the material which passes downwardly throughscreen 76 is separately discharged at 96. A similar discharge 97 isshown on classifier 34, and the remaining sifting units may be similarlyconstructed. A single sifting surface 76 has been shown for purposes ofillustration. Additional surfaces and separate discharge spouts forstocks segregated by such surfaces may be used as desired, provided theopposing units of a given pair are of essentially similar weight andconstruction.

According to a further feature of the invention, a plurality of pairs ofmilling units, such as breaking or reduction machines, are also mountedon the supporting frame. Thus a first pair of such units 98, illustratedas individual roller mills 100 and 102 are mounted at the top of thecentral frame section. These units are further designated by symbols 1Aand IE to show that they are adapted to perform initial millingoperations on two portions of stocks A and B. Different stocks may beused, and different initial operations carried out at 1A and 1B. Thestock to be milled on unit 100 is introduced at 104 and the stock to bemilled on unit 102 is introduced at 106. These first units 100 and 102then discharge their respective milled products at 108 and 110,respectively, into the receiving ends of the uppermost pair of opposedsifters, 32 and 34.

A second pair of milling units is provided, consisting, for example, ofsecond roller mill units 112 and 114 mounted on the respective outerframe portions 22 and 24 to receive the tailings from the respectivesifters 32 and 34. The milling units of this second pair perform desiredoperations, as designated 2A and 2B, on their respective stocks, andthen discharge directly into the receiving ends of the next pair ofclassifiers, 36 and 38.

A third pair of milling machines 116 and 118 are mounted in the centralportion of the frame to receive the tailings from sifters 36 and 38, toperform desired third milling operations 3A, 313 on the respectivestreams, and to discharge the materials processed by such machines intothe receiving ends of the next lower sifters 40 and 42.

Finally, a fourth pair of milling machines, illustrated as rollermilling units 120 and 122, are mounted at the outer frame portions 22and 24 to receive the tailings from sifters 40 and 42, to perform othermilling operations at 4A and 4B on the respective tailings, and todischarge their processed stocks into the receiving ends of the lowestpair of sifters 44 and 46. The tailings of these sifters are thendischarged at 123 for any suitable further processing.

The pairs of milling units are illustrated as each including a singlepair of rolls in special housing and support, as described below. Theserolls 124 and their housing are provided with suitable supportingflanges or pads 126 which can be bolted at 128 to the supporting columnsof the frame. A driving pulley 130 on one of the rolls is connected by asuitable belt 132 to the drive pulley 134 of a motor 136. in this casethe respective roller milling units are driven in pairs and motor 136thus also drives the lower unit 116 by a belt 138. Similarly, a singlemotor 140 at each end of the frame drives the remaining units. Forexample, motor 140 is connected by belt 142 to the roll unit 112, and bybelt 144 to milling unit 120. Similar drive motors are connected tounits 102 and 118 and units 114 and 122 at the other sections of thestack.

The stacked unit illustrated in FIG. 1 is designed for use in suitableclassifying operations of a flour milling process. As suggested above,different stocks can be fed through the respective sections 1A, 2A, 3Aand 4A on the one hand, and sections 18, 2B, 3B, and 4B on the other, toperform different processing steps on different stocks. For example,units 1A, 2A, 3A and 4A could perform successive breaking operations ongrain introduced at 104, while units 13, 2B, 3B and 413 could performsuccessive reduction operations on stocks introduced at 106. Stocks fromother sources can be added at desired points.

If one decides to perform identical operations on similar stocks at eachstep of the apparatus of FIG. 1, the desired initial stock may be fedfrom a common source, and separated by a suitable divider or streamsplitter, as shown schematically at 167, so that substantially equalquantities or volume rates of the same stock are fed to each of therespective initial units 1A and 1B, for essen-' tially similaroperations. For example, such a stacked unit might be used to performfour successive breaking operations with intermediate scalping orsifting of the stocks, and with identical clean wheat fed to each of thefirst units at 104 and 106. Or the unit could receive equal amounts of agiven middlings stock at 104 and 106 and perform successive reductionand classifying operations at the respective steps. In any such case,the use of two identical pairs of rolls or units at each step, and thedivision of the initial feed at 167 equally between the first rollsprovides a particularly advantageous milling unit in which undesiredvibrations are reduced to a minimum and in which each of the pairs ofopposed sifters carries essentially the same load as its oppositemember. Thus a well-balanced, compact unit with minimum vibration isachieved.

According to a further feature of the present invention, a special formof milling roll unit is provided which can be mounted in novel fashionon the vertical columns at the center and ends of the stacked unit.These milling machines are provided with special casings havingsupporting means on the back walls. Thus the machines can be hung orsupported by attaching these back wall portions to vertical columns orother frame members.

As distinguished from conventional milling rolls which have a heavybottom support arrangement, the units of the present invention have aminimum vertical height. Thus, they can be fitted between upper andlower classifying or other processing units, which can be spacedvertically much more closely than could be achieved with conventionalroll stands.

Such roller mill units are also arranged so that all controls and drivesare on their front or end walls and necessary adjustments and repairscan be made while the units remain in position on a stack or frame withsifters located immediately above and below them. Finally,

the particular mounting of these units makes it possible to remove anindividual machine from the stock or frame and replace it by anothersimilar unit to permit convenient repair and maintenance work on theremoved unit without unnecessary interruption of the operation of thecomplete stacked unit.

Details of these individual roller mills are shown in FIGS. 4, 5, and 6,with particular reference to the unit 112 of FIG. 1. Roller mill 112includes a casing or housing portion indicated generally at 146. Thishousing includes end support sections 148 and 150 in which suitablebearings for the milling rolls are carried. The central portion of thehousing at 152 encloses the milling rolls themselves.

An indicated above, the unit is adapted to be supported by means on therear wall 154 of the unit. Such supporting means include lower and uppersupporting pads 126 and 128, respectively, on the end portion 148 of theeasing, and similar supporting pads 156 and 158 on the opposite endportion 150. These supporting pads are provided with a plurality ofopenings 160 through which retaining bolts 162 are inserted to securethe supporting pads to appropriate frame members of the stacked unit,such as vertical columns 22. Y

The respective end portions 148 and 150 preferably include supportingwalls or webs 164 and 166, in which suitable bearings 168 are providedto support the shafts 170 and 172 of the respective milling rolls 174and 176. The bearings may be removable in known manner to permit removalof the individual milling rolls for replacement or repair. Thesesupporting webs or walls 164 and 166 are preferably located opposite therespective supporting pads to provide a direct supporting connectionbetween the supporting pads and the bearing supports in the casing. Thecasing itself is cast or otherwise constructed to provide walls and ribsof appropriate thickness to support the roll bearings from the rear wallsupporting pads.

As shown in FIG. 4, one of the roll shafts 170 projects outwardly beyondat least one end wall or cap 178 of the casing and is provided with asuitable pulley or sheave 180 adapted to be driven by belt 142. At theopposite end of the casing at 150, suitable connections can be providedto obtain the desired differential speeds for the respective rolls. Thusthe roller shafts 170 and 172 carry respective sprockets 182 and 184which are interconnected by a suitable driving chain 186. This chain maypass over the two sprockets on the roll shafts and over additional idlersprockets 188 and 190 mounted on the supporting wall 166 as shown. Aremovable end plate 192 closes the end 159 of the housing and providesconvenient access to the diiferential mechanism as needed.

To feed the stock to the rolls, a suitable inlet opening 194 is providedin the top wall of the central casing portion above the rolls. Asuitable inlet tube or hopper 196 may be added to connect this opening194 to the discharge end of a suitable sifter or to any other source ofmaterial for the milling unit 112. The inlet opening and tube may be ofconventional circular configuration, located at the center of the topwall. In this case, however, a hopper of elongated cross section isshown. Thus the material discharged by a sifting unit just above theroller mill 112, as the sifter 32 of FIG. 1, may already be distributedover a width equivalent to that of the milling rolls. The use of a wideor elongated inlet and hopper at 194 and 196 takes advantage of suchdistribution and imposes a smaller burden of distribution on the feedingmechanism of the roller mill itself. The stock received through opening194 is further distributed by a suitable feed roller 198 in knownmanner, so that an even layer of material is fed between the millingrolls 174 and 176.

Immediately below the milling rolls the bottom wall 200 of the casingincludes a laterally extending opening 202 through which the material isdischarged directly by gravity. To guide the material from this bottomopening to a subsequent processing unit, the bottom wall is alsoprovided with supporting brackets 204, to which a discharge hopper 206may be secured by bolts 208. Hopper 206 and bottom opening 202 are alsoillustrated with elongated cross sections to retain the lateraldistribution of the stock, if desired, as the stock is fed to asubsequent processing unit. In such case, the inlet of the subsequentunit should be of generally similar width. Thus the lateral distributionof the stock can be maintained throughout a series of enclosedprocessing units as illustrated by the closed reciprocating sifterbodies and the closed roller mill casings.

The milling machine includes one or more adjusting wheels 210 and 212 atits front wall 214 for convenient adjustment of the roll spacing or rollthrowout mechanism in known manner. The front wall 214 also includes aremovable or transparent inspection door 216 through which a miller maycheck the condition of the stock leaving the rolls. Another removablecover .218 is located at the upper portion of the casing for inspectionof the operation of the feeding mechanism 198 or, in appropriate cases,for actual removal of the rolls in known manner. Automatic roll throwoutmechanism, automatic feed control and other features of conventionalroller mills may also be incorporated as needed or desired.

Thus a convenient roller milling unit has been provided in which asingle pair of milling rolls is mounted with appropriate drivingmechanism in a single housing and the rear wall of the housing isprovided with supporting means by which the unit can be hung on asuitable frame member with minimum vertical clearance between upper andlower processing units.

According to the foregoing description, a compact stacked mill unit hasbeen described which is particularly advantageous in the milling ofwheat and other grains. Such a unit provides a plurality ofreciprocating sifters in a compact frame, with the sitters supported inpairs for reciprocation in counter-balancing opposition to each other.The special roller mill housing and construction features and thearrangements for supporting such roller mills by suspension of theirrear walls from a stack or frame contribute to an improved installationin which stock may be subjected to a series of milling operations withminimum intermediate handling. The short vertical height of such rollermilling units contributes to an assembly in which direct gravity flow ofmaterial may take place through a substantial number of verticallyspaced milling and classifying units to provide an enclosed processingsystem of minimum overall height. The present specification hasaccordingly set forth certain of the principles of the present inventionand some of the Ways in which the invention may be put into practice.

Now, therefore, what is claimed is:

l. A stacked fiour milling unit for a grain milling installation, saidunit comprising a supporting frame having aligned center and endportions, a pair of first roller milling machines, each machine having apair of milling rolls, said machines being mounted at the top of saidcenter portion, means for feeding desired stocks to each of saidmachines, two opposed and aligned first longitudinally reciprocatingsubstantially horizontal classifiers supported on said frame beneathsaid first rolls and extending outwardly toward said end portions, meansfor reciprocating said first classifiers in counterbalancing oppositionto each other and thereby separately moving stock received from therespective first roller milling machines outwardly to the end portionswhile the stock is at least partially classified, a pair of secondroller milling machines located one at each end portion of the frame inposition immediately below said first classifiers to receive desiredstock by direct gravity discharge from the outer ends of the respectivefirst classifiers, a second pair of opposed and aligned longitudinallyreciprocating substantially horizontal classifiers supported on saidframe independently of said first classifiers with their outer receivingends immediately beneath said second roller milling machines andextending inwardly toward said center portion, means for reciprocatingsaid second classifiers in counterbalancing opposition to each other andthereby separately moving the stock received from the respective secondroller milling machines inwardly to the center portion of the frame,while further classifying said stock, a third pair of roller millingmachines mounted on the central frame portion, means for feeding stockfrom the inner ends of said second classifiers into their respectivethird roller milling machines, a third pair of opposed and alignedlongitudinally reciprocating substantially horizontal classifierssupported on said frame beneath said third roller milling machines andextending from said center portion outwardly to the respective endportions, means for reciprocating said third classifiers incounterbalancing opposition to each other and thereby separately movingthe stock received from the respective third roller milling machinesoutwardly to the end portions while the stock is further classified, twofourth roller milling machines mounted one at each end portion of theframe in position immediately below the third classifiers to receivedesired stock by direct gravity discharge from the outer ends of therespective third classifiers, a fourth pair of opposed and alignedlongitudinally reciprocating substantially horizontal classifierssupported on said frame immediately beneath said fourth pair of rolls,and means for reciprocating said fourth classifiers in counterbalancingopposition to each other and thereby separately moving the stockreceived from the respective fourth roller milling machines inwardly tothe center portion of the frame while further classifying said stock.

2. A stacked flour milling unit according to claim 1 in which said thirdpair of roller milling units is mounted on the central frame portion ata location positioned below the inner ends of the second pair ofclassifiers to receive stocks therefrom by direct gravity discharge,said third pair of milling units also being positioned immediately abovethe inner ends of the third pair of classifiers to deliver stocksthereto by direct gravity discharge.

3. A stacked flour milling unit according to claim 1 in which said meansfor feeding stocks to each of the first pair of roller milling unitsincludes means for receiving a single type of stock and dividing it tofeed such stock to each of said first milling units at substantiallyequal volume rates.

4. A grain milling installation for performing a series of breakoperations comprising at least one stacked flour milling unit accordingto claim 1, said unit having four pairs of break roller millingmachines, one pair for each of first, second, third and fourth breakoperations.

5. A grain milling installation for performing a series of reductionoperations comprising at least one stacked flour milling unit accordingto claim 1, said unit having four pairs of reduction roller millingmachines, one pair for each of four successive reduction operations.

References Cited in the file of this patent UNITED STATES PATENTS 97,038Buchholz Nov. 23, 1869 263,164 Gilbert et al. Aug. 22, 1882 267,347Hollingsworth Nov. 14, 1882 505,723 Pollock Sept. 26, 1893 806,865Benesh Dec. 12, 1905 1,377,976 Smith May 10, 1921 2,081,283 Ryan et al.May 25, 1937 2,085,376 Maede June 29, 1937 FOREIGN PATENTS 4,478 GreatBritain of 1908 13,101 Great Britain of 1891 197,266 Switzerland July16, 1938 764,643 France Mar. 12, 1934

